In an apparatus as an image forming apparatus, a measurement device, an electronic device, and an electric appliance, various type of supporting legs attached to the bottom of the apparatus is disclosed in the related art as following: Japanese Examined Patent Application No. 1992-40198, Japanese Patent Laid-Open Application No. 2001-22142, Japanese Patent Laid-Open Application No. 2001-51462, and Japanese Patent Laid-Open Application No. 2002-287452.
Specifically, the Japanese Patent Laid-Open Application No. 2001-51462 discloses an image forming apparatus that includes: a first abdominal plate having a bottom portion to which the first supporting leg or second supporting leg is provided, a second abdominal plate having a bottom portion that the first supporting leg or second supporting leg is provided, and connection plates that connect the first abdominal plate and the second abdominal plate.
More specifically, the Japanese Patent Laid-Open Application No. 2001-51462 discloses an image forming apparatus in which the supporting legs make a substantial triangle including the vertical projection of the center of gravity of the device on the installation surface.
The supporting leg should be disposed to keep the apparatus stably on the installation surface by considering the center of gravity of the apparatus. For example, in the apparatus having three supporting legs attached to the bottom of the apparatus which make a triangle on the installation surface, it is preferable that the triangle is made to include the vertical projection of the center of gravity of the apparatus.
The center of gravity of some apparatuses change by altering the configuration of the apparatus, as described below.
The image forming apparatus is configured by a main unit and an adjunct unit. The main unit may be a basic unit and the adjunct unit may be an optional unit. Generally, the center of gravity is widely moved when the optional unit is added to the basic unit. If the position of the supporting legs provided to the image forming apparatus is defined by considering only the center of gravity of the image forming apparatus having the basic unit, the image forming apparatus having the basic unit and the optional unit mounted on the basic unit may not be set stably on the installation surface. In contrast, if the position of the supporting legs are defined by considering only the center of gravity of the image forming apparatus having basic unit and the optional unit, the image forming apparatus having only the basic unit may not be set stably on the installation surface.